Hall Technique
No caries removal and seal using the Hall Technique
Suitable for:
- a primary tooth with an advanced lesion in an occlusal or proximal surface
Aim: To completely seal a carious lesion so that the environment of the plaque biofilm is altered sufficiently to slow or even arrest caries progression.
There is evidence, including some research from primary care, that this approach can be effective, and is preferred to complete caries removal techniques by children, their parent/carer and dentists.84
This technique involves sealing caries into primary molars with a preformed metal crown (PMC). No local anaesthesia, tooth preparation or caries removal is used and therefore there is little risk of iatrogenic damage to adjacent teeth. This technique is only suitable when there is unaffected dentine between the lesion and the pulp, as observed clinically and radiographically, and its success is dependent on the quality of the seal. If the seal fails, caries will progress.
Images show caries in a lower E (left) sealed in with a PMC using the Hall Technique (right)
Only an outline of the technique is given below. Before using it, refer to the Hall Technique User’s Manual.
Early detection of multi-surface lesions with radiographs before there is marginal ridge breakdown will facilitate their management with the Hall Technique because PMCs can be more difficult to satisfactorily fit if the mesio-distal width has been reduced due to mesial migration of the tooth behind.
Outline of the Hall Technique
Ensure the child is sitting upright.
Assess whether separators are required.
- Although placing separators requires a second visit (e.g. 3-5 days later) to remove them and to fit the crown, some clinicians find they ease the fitting of a crown using the Hall Technique.
- Separators might be required where there is a broad tight contact between adjacent teeth.
If there is any possibility of the crown endangering the airway during fitting, make a ‘handle’ for it with a strip of sticking plaster, or ensure the airway is protected with gauze.
Select the correct size of PMC.
- Do not seat the crown through contacts prior to cementation as it might be difficult to remove.
Ensure the PMC is well filled with a glass ionomer luting cement.
Seat the PMC over the tooth.
- Seating can be assisted by the child biting on the crown or on a cotton wool roll placed on the crown.
Ask the child to open, check the crown is seated evenly over the tooth and through the contacts and ask them to bite down hard again (or press hard to complete the seating).
Remove excess cement and clear the contacts using floss.
Avoid excess cement reaching the tongue because it has a very bitter taste that children dislike.